05Alert banner slide-in — the banner's position value moves down from off-screen once repeated failures cross a threshold

<main class="stage">
<div class="abs is-demo" id="abs">
  <div class="abs__banner" id="absBanner">Repeated login attempts detected</div>
  <div class="abs__card">
    <span class="abs__label">Repeated failures <b id="absFails">0</b>times</span>
    <button class="abs__btn" id="absBtn" type="button">Simulate failed login</button>
  </div>
</div>
</main>

@use "../../../../site/static/demo-tokens" as *;

// 계산 겹: 배너 위치를 스프링-감쇠 물리로 적분(강성·감쇠·질량) — index.html 참조
@include stage($stage-yellow);

.abs {
  position: relative;
  width: 100%;
  max-width: 340px;
  min-height: 180px;
  display: grid;
  align-content: end;
  overflow: hidden;
  border-radius: $r-card;
  background: $subject-cream;
}

.abs__banner {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  transform: translateY(-60%);
  background: $error;
  color: $subject-cream;
  padding: $sp-3 $sp-4;
  font: 700 13px/1.4 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  text-align: center;
}

.abs__card {
  display: grid;
  gap: $sp-3;
  justify-items: center;
  padding: $sp-6 $sp-4 $sp-5;
}

.abs__label {
  font: 600 13px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  color: $stage-ink;
}

.abs__label b { font-size: 16px; font-variant-numeric: tabular-nums; }

.abs__btn {
  border: 0;
  border-radius: $r-control;
  padding: $sp-2 $sp-4;
  background: $stage-ink;
  color: $subject-cream;
  font: 700 14px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  cursor: pointer;
  transition: transform $dur-instant $ease-out;

  &:active { transform: scale(.96); }
}

@media (max-width: 340px) {
  .abs { max-width: 220px; min-height: 150px; }
  .abs__banner { font-size: 12px; }
}

@media (prefers-reduced-motion: reduce) {
  .abs__btn { transition: none; }
}

html, body {
  margin: 0;
  overflow: hidden;
}

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #ffd23f;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.abs {
  position: relative;
  width: 100%;
  max-width: 340px;
  min-height: 180px;
  display: grid;
  align-content: end;
  overflow: hidden;
  border-radius: 16px;
  background: #fff7e6;
}

.abs__banner {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  transform: translateY(-60%);
  background: #c2361a;
  color: #fff7e6;
  padding: 12px 16px;
  font: 700 13px/1.4 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  text-align: center;
}

.abs__card {
  display: grid;
  gap: 12px;
  justify-items: center;
  padding: 24px 16px 20px;
}

.abs__label {
  font: 600 13px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  color: #17141a;
}

.abs__label b {
  font-size: 16px;
  font-variant-numeric: tabular-nums;
}

.abs__btn {
  border: 0;
  border-radius: 12px;
  padding: 8px 16px;
  background: #17141a;
  color: #fff7e6;
  font: 700 14px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  cursor: pointer;
  transition: transform 140ms ease-out;
}
.abs__btn:active {
  transform: scale(0.96);
}

@media (max-width: 340px) {
  .abs {
    max-width: 220px;
    min-height: 150px;
  }
  .abs__banner {
    font-size: 12px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .abs__btn {
    transition: none;
  }
}

(function () {
  var root = document.getElementById('abs');
  var btn = document.getElementById('absBtn');
  var failsEl = document.getElementById('absFails');
  var banner = document.getElementById('absBanner');

  // 상수: 배너가 뜨는 Fail 기준 · 스프링 물리(강성·감쇠·질량)
  var THRESHOLD = 3;
  var SPRING_K = 180;
  var SPRING_C = 18;
  var SPRING_M = 1;

  var fails = 0;
  var pos = -60;   // 배너 위치(%, 음수 = 화면 밖 위)
  var vel = 0;
  var target = -60;
  var rafId = null;

  // 계산 겹: 반암시적 오일러 스프링 적분 — 속도 += (-k·변위 − c·속도)/질량·dt, 위치 += 속도·dt
  function tick(ts, last) {
    var dt = Math.min(32, ts - last) / 1000;
    var disp = pos - target;
    var acc = (-SPRING_K * disp - SPRING_C * vel) / SPRING_M;
    vel += acc * dt;
    pos += vel * dt;
    banner.style.transform = 'translateY(' + pos.toFixed(2) + '%)';
    if (Math.abs(disp) > 0.3 || Math.abs(vel) > 0.5) {
      rafId = requestAnimationFrame(function (t) { tick(t, ts); });
    } else {
      pos = target;
      banner.style.transform = 'translateY(' + pos.toFixed(2) + '%)';
    }
  }

  function spring(to) {
    if (rafId) cancelAnimationFrame(rafId);
    target = to;
    rafId = requestAnimationFrame(function (ts) { tick(ts, ts - 16); });
  }

  function fail() {
    fails += 1;
    failsEl.textContent = String(fails);
    if (fails === THRESHOLD) spring(0);
  }

  function reset() {
    fails = 0;
    failsEl.textContent = '0';
    spring(-60);
  }

  btn.addEventListener('click', function () {
    root.classList.remove('is-demo');
    stopAutoplay();
    fail();
  });

  var autoTimer = null;
  function autoTick() {
    if (fails >= THRESHOLD) { reset(); return; }
    fail();
  }
  function stopAutoplay() { if (autoTimer) { clearInterval(autoTimer); autoTimer = null; } }
  var reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;
  if (!reduce) { autoTimer = setInterval(autoTick, 420); }
})();

import { useEffect, useRef } from "react";
import styles from "./AuthAttemptAlertBannerSlide.module.scss";

type Box<T> = { current: T };

export default function AuthAttemptAlertBannerSlide() {
  const rootRef = useRef(null) as unknown as Box<HTMLDivElement | null>;

  useEffect(() => {
    const root = rootRef.current;
    if (!root) return;
    const btn = root.querySelector(`.${styles.btn}`) as HTMLButtonElement | null;
    const failsEl = root.querySelector(`.${styles.fails}`) as HTMLElement | null;
    const banner = root.querySelector(`.${styles.banner}`) as HTMLElement | null;
    if (!btn || !failsEl || !banner) return;

    // 상수: 배너가 뜨는 실패 기준 · 스프링 물리(강성·감쇠·질량)
    const THRESHOLD = 3;
    const SPRING_K = 180;
    const SPRING_C = 18;
    const SPRING_M = 1;

    let fails = 0;
    let pos = -60;
    let vel = 0;
    let target = -60;
    let rafId: number | null = null;

    // 계산 겹: 반암시적 오일러 스프링 적분 — 속도 += (-k·변위 − c·속도)/질량·dt, 위치 += 속도·dt
    function tick(ts: number, last: number) {
      const dt = Math.min(32, ts - last) / 1000;
      const disp = pos - target;
      const acc = (-SPRING_K * disp - SPRING_C * vel) / SPRING_M;
      vel += acc * dt;
      pos += vel * dt;
      banner!.style.transform = "translateY(" + pos.toFixed(2) + "%)";
      if (Math.abs(disp) > 0.3 || Math.abs(vel) > 0.5) {
        rafId = requestAnimationFrame((t) => tick(t, ts));
      } else {
        pos = target;
        banner!.style.transform = "translateY(" + pos.toFixed(2) + "%)";
      }
    }

    function spring(to: number) {
      if (rafId !== null) cancelAnimationFrame(rafId);
      target = to;
      rafId = requestAnimationFrame((ts) => tick(ts, ts - 16));
    }

    function fail() {
      fails += 1;
      failsEl!.textContent = String(fails);
      if (fails === THRESHOLD) spring(0);
    }

    function reset() {
      fails = 0;
      failsEl!.textContent = "0";
      spring(-60);
    }

    function onClick() {
      root!.classList.remove(styles["is-demo"]);
      stopAutoplay();
      fail();
    }
    btn.addEventListener("click", onClick);

    let autoTimer: number | null = null;
    function autoTick() {
      if (fails >= THRESHOLD) { reset(); return; }
      fail();
    }
    function stopAutoplay() { if (autoTimer !== null) { window.clearInterval(autoTimer); autoTimer = null; } }
    const reduce = window.matchMedia("(prefers-reduced-motion: reduce)").matches;
    if (!reduce) { autoTimer = window.setInterval(autoTick, 420); }

    return () => {
      stopAutoplay();
      if (rafId !== null) cancelAnimationFrame(rafId);
      btn.removeEventListener("click", onClick);
    };
  }, []);

  return (
    <div ref={rootRef} className={`${styles.stage} ${styles.abs} ${styles["is-demo"]}`}>
      <div className={styles.banner}>이상 로그인 시도가 반복되었습니다</div>
      <div className={styles.card}>
        <span className={styles.label}>반복 실패 <b className={styles.fails}>0</b>회</span>
        <button className={styles.btn} type="button">로그인 실패 시도</button>
      </div>
    </div>
  );
}